Sans's Father Complex
by FlamingFlyingFoxOfDoom
Summary: The kids could be different, but they usually had the same attitude. It usually was the same routine. But this one broke the usual shtick. This boy smiled at him as if nothing was wrong, even if his eye was black and blue.
1. Chapter 1

**A/N**

 **Technically this is a crossover, but saying there's only one element from the second story (Jude Mathis from Tales of XIllia) I decided to keep it under strictly Undertale.**

 **Enjoy!**

* * *

Sans stood ankle-deep in the snow, hands buried deep in his pockets with his spine pressed to the trunk of a tree. Chest rising and falling, he enjoyed the crisp air that blew threw his ribs. The snow fell from an unknown source, peppering his face with its cold.

When he heard the sound of the door opening, he sighed, watching a puff of smoke float up from his teeth. Time for work.

He peered around the tree trunk, taking in a quick study of the child. He tilted his skull a bit.

It was a different kid than usual. Black hair instead of brown, a blue-and-red striped sweater instead of aqua-and-pink and sweatpants instead of shorts. The child was wiping at his eyes, breathing in slowly through his mouth. His hair was ruffled, sticking up at the ends and a bruise graced his cheek, as well as under his eye.

Sans shrugged.

Sometimes the kid was different, it didn't matter. He cleared his non-existent throat and shifted his feet, preparing for his rehearsed entrance. The child reach Papyrus's 'gate', and Sans clenched a fist, trapping the boy there with blue magic. He tugged at his legs a few times, staring down at his feet with a baffled expression. As he struggled, Sans trotted up behind him.

" _Human…."_ He started the usual shtick _"Don't you know how to greet a new pal? Turn around and shake my hand."_

He offered his hand, watching with an amused grin as the boy shakily took the hand offered to him. The whoopee cushion did its job, letting out a pleasant and comical puff of air. Sans chuckled.

"The ol' whoopee-cushion-in-the-hand trick" He grinned down at the boy. The child covered his mouth with one hand, giggling into his cupped fingers. Sans grinned wider "Gets 'em every time. Heya, kid. I'm Sans. Sans the Skeleton. So-"

"Nice to meet you, Mr. Sans." The boy said softly, smiling and unaware he cut the skeleton off. "I'm Jude. Jude Mathis."

Sans blinked "Er….Heya. So, Jude, you're a human, right?"

"That's right." Jude nodded. His smile dropped to a frown as he took a cautious step back "…Why?"

"Well…" Sans shrugged "I just think it's hilarious and all. Say, thing is, I'm supposed to be on the hunt for humans now- Easy there, kid" He muttered, grabbing the boy by the collar of his sweater "I ain't gonna hurt ya, okay? I don't care too much for catching humans."

"Oh." Jude blushed. He smiled "Sorry."

Sans laughed "Er….Right."

And after that, Jude strayed further and further from the norm. While the boy wasn't quite _talkative_ , he did speak more than the usual child. And not only that, he was much too…. Well…

"Er-Excuse me, Mr. Papyrus!" The boy stammered, cradling the orb in his arms "Your footprints kind of left a path in the snow, so I know where to go…."

"OH. …SIMPLY IGNORE THAT THEN."

…

Honest.

Sans sighed, scratching the side of his skull as Jude walked by. The boy seemed to spot him, waving ever so timidly in his direction. Sans shrugged and waved back.

Eventually, him and Papyrus waited for the human child at the bridge. They waited an waited and waited, until eventually Sans found himself being shaken awake by his brother.

"SANS!" Papyrus frowned "D-DO YOU THINK THE HUMAN'S OKAY?"

" 'm sure he's fine, bro." Sans shrugged "He's probably petting the dogs or something." It wasn't uncommon that a kid would spend hours on end petting Lesser Dog.

"HM…. I'M GOING TO GO LOOK FOR HIM." Papyrus decided, walking off as he finished his sentence. Sans shrugged and followed him, hands buried deep in his pockets as his eyelids fluttered shut once again. He was rudely awaken, however, by running into Papyrus's back as he abruptly halted. "OH MY GOD! JUDE!"

The taller skeleton sprinted off, kicking up the snow that pelted Sans in the face. With an annoyed grunt, he wiped the pesky white stuff off his face. He rolled his eyes, listening to Papyrus's rambling form.

 _He probably scraped his knees or something._ Sans thought cynically.

"SANS!" Papyrus hollered. Sans trotted up, peering around his brother to look at the human-

" _HOLY SHIT-"_

"SANS WATCH YOUR LANGUAGE!"

"Yeah, yeah, sorry! Crud, kid-!" He stared, rushing over to the child's side. Jude turned away shyly, blushing lightly. Whether it was from the cold or embarrassment was unclear.

"It's nothing, I'm okay-"

"YOU OBVIOUSLY ARE NOT!" Papyrus screeched "SANS, ISN'T THE RED STUFF SUPPOSED TO STAY _INISDE_ THE HUMANS!?"

"Yep!" Sans choked.

The boy's left side was slick and warm with blood, and he clutched tightly to his left arm as if to tourniquet it with his own grip. He took a step away from the skeletons.

"I'm fine, really…."

"Er- Kid-" Sans sighed, turning to Papyrus "Bro, go get some bandages and antiseptic, alright?"

"ER…" Papyrus nodded after a moment, turning on heel and bolting off. Sans sighed, taking a moment to teleport away and to come back with the supplies needed to treat the boy. Jude's eyes widened a bit at his return, but he didn't do much more than that.

Sans pulled the boy up onto his lap and set himself to dressing the wound. Jude tensed up at the touch.

"Er…you okay, kid?" Sans asked, unraveling the bandages.

The kid was trembling, or maybe the skeleton was imagining it, but he slowly nodded. "Y-yeah. Sorry."

"Don't apologize." Sans muttered "Y'didn't do anything wrong."

"Sorry."

Sans sighed. "Right. Stay still."

"Okay." Jude said, looking away. Sans felt his bones rattle a bit, unsettled by the child's demeanor. The man shook his head and focused on the task at hand. He rolled up Jude's red-dyed sleeve, muttering an apology as the child hissed out in pain, and revealed the deep gash that carved into the child's arm.

"Yeesh." Sans grimaced, dabbing at the cut with a damp rag "How did _this_ happen?"

"It was an accident." Jude explained quickly.

"An _accident?"_ Sans quoted, eyeing the wound. It was always puffy and agitated, skin reddened from cold and exposure. But it was far too clean a cut. Practically a vertical bloody line from his shoulder to his wrist. The edges of the wound was already beginning to scab over. "Kid, I don't think-"

"Jude!" Someone called. Sans and Jude looked up to watch a monster with trees for antlers sprint over, bandages wadded up in its lopsided mouth. Gyftrott. It skidded to a halt in front of the duo. "Oh wow, Sans! Thank goodness. You can help him, right-"

Sans held up a hand to silence the monster, then flicked his wrist to motion to the boy's wound "How'd this happen?"

"E-er…" Gyftrott swallowed, shuffling its feet "E…I….I attacked him-"

"It was an accident." Jude insisted.

"Okay, okay." Sans muttered, waving down both members of his company down "Both of you need to calm down. One at a time. Jude, what's yer story?"

"Like I said" Jude frowned "It was an accident. They didn't mean to hurt me, they just slipped."

"Okay. Gyftrott?"

The deer shuffled its hooves again, looking down to the snowy ground "I…Well, he's a human, y'know? So I figured I oughtta….then…. I, well….."

"You gouged out a good chunk of his arm." Sans finished the sentence as the monster flinched.

"Yeah."

Jude frowned, reaching out with his good arm to pat the creature on his head "Hey, don't worry about it. I'm fine." He smiled "See?"

Sans felt his figurative heart sink as the boy reassured the monster.

There was no way this kid was gonna make it out of the mountain alive.


	2. Chapter 2

After that whole fiasco was over with, Papyrus wasn't too keen on having the kid face The Gauntlet of Deadly Terror. In fact, the thought seemed to upset him. Which really wasn't surprising. Papyrus never wanted the human to go through that elaborate trap. Sans expected that.

So, on Papyrus's orders, Jude was staying the night at their house. Papyrus set about to setting up the couch to be as cozy as possible, and then took it upon himself to clean Jude's bloodied sweater. So the kid was stuck in his black undershirt, wrapped up in a soft blanket with a cup of cocoa nestled in between his hands.

Sans rolled his shoulders back, plopping down next to Jude on the couch. The boy sipped at his hot beverage. His face was flushed from the cold, his nose reddened. The constant snivels was a clear indication of where he had been.

"So, Jude." Sans yawned. The boy looked at him, tilting his head ever so slightly. "What brings ya down a mountain?"

"Oh…"Jude shrugged, turning his gaze away "Just…thought I'd drop by."

Sans chortled, smacking his hand over his mouth before it became a cackle. Through his snickers, he rose a bone-brow to the brow. "Was….was that a pun?"

Jude's face somehow grew redder "Er….y-yeah."

"Nii _iiiii_ icce." Sans laughed, giving him a thumbs up. The boy stared at his hand a moment. A frown flashed on his face a moment, but was quickly swapped out for a small smile.

"Do….do you _like_ puns?" He asked, eyes bright.

"Heck yeah. I love 'em." Sans grinned, winking at the boy "I tell a skele- _ton_ of 'em."

It was Jude's turn to snicker, curling in on himself deeper into his blankets. His eyes were locked on Sans's, bright and shining bronze. Sans grinned wider and buried his hands further into his shorts.

"Did ya find that _humerus?"_ he winked " _Tibia_ honest, I think it's a bit overused. But I guess I shouldn't be so _sternum_ about it."

Jude's giggled rose into a laugh. A high, bleating thing. Almost like a goat. Except a bit lower and a bit less goaty and a bit more humany. He was laughing so hard, in fact, he spilt his cocoa on the couch.

"Woah!" Sans jerked away on reflex the same time Jude did, avoiding the scalding liquid as it further stained the already stained couch cushions.

"I-I'm sorry!" Jude stammered, turning away quickly. Sans waved him down.

"It's okay, kid, accidents happen-" He stopped suddenly.

Did…

Did he imagine that? Or did the kid just _flinch?_

"I'm sorry." Jude repeated, worming his way out of his blanket "I'll go get something to clean it up-"

"Kid, don't worry about it." Sans interrupted, the corners of his grin twisting downwards "I spill stuff on this couch all the time."

Jude stared at him a moment before he nestled back into the couch cushions. His eyes were locked on the mug in his hands.

"A…are you sure it's all right?" He asked, sparing only a quick glance in Sans's direction.

"Sure I'm sure." Sans said, shrugging. He winked "Though, actually, I'm Sans."

Jude stared at him a moment. Then his small smile was back, set under those bronze eyes of him. He laughed. But not a lot. Then he simply fidgeted, kicking his feet up and down.

"Er…Mister Sans, can I ask you something?" he asked.

"Y'just did." Sans pointed out, grinning. Jude laughed a little, but again, not much.

"Yeah…But, what I mean is, why do the Monsters hate humans so much?" He stared up at the skeleton, tilting his head ever-so-slightly to one side, his bruised eye up. "I can tell they don't think too highly of us. Why is that?"

Sans sighed, looking away "Observant kid, aren'tcha?"

"Sorry."

"Yeesh." Sans pouted, his eyes flicking back over to the boy "Y'don't gotta apologize. Y'didn't do anything wrong."

"Oh." Jude fidgeted, blushing "Sorry- er-"

"Okay, okay, that's enough 'sorrys'." Sans sighed. He nestled into the couch, hunching his shoulders. "Er…well…" he sighed again, clenching and unclenching his fists in his pockets. "We kinda got sealed down here by them, y'know? So….most monsters are kinda….mad."

"…Oh." Jude said. That's all he said. He turned away again, uneager to maintain eye contact. He still asked "So why don't you and Papyrus hate me?"

Sans felt his bones stiffen. He forced a shrug "Eh. Pap's too good to care about that kind of thing."

"And you?"

Sans's bones rattled. His SOUL felt as if some unseen pressure was squeezing it. Even if he did have lungs, he was sure he couldn't breathe. "…I'd be lyin' if I said I was fond of 'em."

"Oh." Was all he said.

Sans gritted his teeth. He hadn't known too many humans in his lifetimes. But the ones he did know… Well. There was always a knife involved at some point. There was a smiling mask, holes in the hands. A low voice either saying 'it'll be over soon' or 'but nobody came'. A golden hall. A dark basement. Gushing red that seeped through his ribs and soaked his shirt, plastering it to his chest. A stinging pain that started where the bones were cut but then spread, spread deeper and deeper until the only thing he could know was _pain-_

"Mister Sans?" said the boy's voice, dragging Sans out of those vague memories and looking eye-to-eye with one of those humans he so loathed. But…

This wasn't a red-eyed child.

This wasn't a man in a mask.

This was Jude. Frowning. Small hand on his own skeletal one. A bruise gracing his eye, another on his cheek. His hair sticking up in a frenzy. The stocky skeleton had a sudden urge to ruffle it back into place that he quickly suppressed. The boy's bronze eyes were dark with concern, frantically struggling to meet the pinpricks of light in his sockets.

"Er… heya kid." Sans said, hitching up his grin "What's with the look?"

Jude blinked "Are you okay?"

"Wha?" Sans said. He shook his skull slowly, pushing the kid away from him "You're askin' me if _I'm_ okay when yer the one all banged up?"

Jude nodded. Then frowned "Is that bad?"

Sans sighed. "Nah, kid, it's cool." Sans said "Just be sure to take care of yerself."

Jude tilted his head. His frown stuck outwards into a pout "Don't treat me like a kid."

"Well, kid, I hate to tell ya this" Sans winked "but you _are_ a kid."

Jude rolled his eyes, settling back down on the couch and hunching the blanket over his small form. Sans rolled his shoulders back, enjoying the _crack_ of his joints as they were moved out of place. Mettaton was up to some nonsense on TV. Jude seemed to be as disinterested as he was, instead eyeing the pile of socks in the corner, as most of the kids did.

His eye sockets fluttered shut as Papyrus raced down the stairs, declaring

"HUMAN, I HAVE CLEANED AND MENDED YOUR SWEATER!"

It wasn't until later that evening, when Papyrus shook him awake, that he, well, woke up. Sans grinned up at the annoyed glare of his brother, yawning to add to the effect.

"'Mornin'." He grinned.

"IT'S NINE AT NIGHT!" Papyrus yelled, stomping his foot. The younger brother was already in his pajamas, it looked like. For some reason he wore a pair of stripped boxers on his head. But who was Sans to critique fashion?

"Oh." Sans chirped "'Night, then."

Papyrus pouted "BUT SANS-"

"I know, I know." Sans chuckled, pushing himself up off the couch. "Bedtime story time, right?"

Papyrus's face brightened "YES! I'M SO GLAD YOU REMEMBERED- OH! HUMAN!" his attention shifted as Jude hopped down the stairs. The boy flinched at the volume of Papyrus's voice, but met his eye sockets.

"Yeah?" He blinked.

"WOULD YOU CARE TO JOIN ME AND SANS FOR BEDTIME STORIES?" Papyrus asked, practically vibrating with how eager he was.

"'Bedtime stories'?" He repeated with a tilt of his head.

"SO YOU WOULD LIKE TO JOIN US! EXCELLENT!" Papyrus cheered, scooping up the boy who let out only a small squeak of protest before he raced up the stairs. Sans rolled his eyes fondly, trudging up after them.

As he entered the room he found the duo snuggled deep into the blankets of Papyrus's racecar bed. Jude, nestled into the crook of one of Papyrus's arms, stared widely, vastly confused as he looked at Sans, clearly hoping for some sort of answer or explanation. Papyrus was excitedly bouncing, practically vibrating.

"So…" Sans grinned, burrowing his hands in his pockets "What book should I read tonight?"

"OH! OH!" Papyrus yelled "HOW ABOUT FLUFFY BUNNY GOES TO THE CIRCUS?"

"Sure." Sans said. He trotted over to Papyrus's bookshelf, grabbed the mentioned book, and trotted back to the bed. He sat on its edge, making sure that his audience could see the pictures. Jude blinked, staring.

Sans was particularly fond of Fluffy Bunny himself, but he was fond of how much Papyrus enjoyed it. It was a boring, simple storyline with lots of water-color pictures and very few words. But he read them slowly and melodiously, putting his own spin on the voices and the narration. He kept reading out of habit even after he heard Papyrus's snores fill the room. As he whispered 'the end' and closed the book, he felt a gentle tug on the end of his sleeve. Blinking, he looked down at the small human.

Jude looked away from him, a light blush on his cheeks. His voice was quiet as he asked "Can you read another?"

Sans thought a moment, then shrugged "Sure."


	3. Chapter 3

Sans watched, hands in his pockets, from the shelter of the thick fog that always seemed to cover this stretch of road. The warmer water from Waterfall clashed with the cold air of Snowden, causing a thick blanket of mist. He felt that Jude wouldn't do anything to Papyrus, but other kids had made him think that too.

The boy left the home that morning, persistent to find Gyftrott and assure them that he was fine. But now, he was on the way to Waterfall. With only Papyrus in his way.

Jude approached.

Papyrus did his whole spiel. Then their battle began. Jude stood his ground, jumping over the small bones that slid into his path. After the small bones, his SOUL turned blue and the larger ones raced towards him. Those, he wasn't too lucky. He managed to dodge a couple, weaving in between them instead of jumping. A different approach. But not unheard of.

Mid-dodge, Jude's foot slipped on some bare ice. He fell face-first into the snow as an army of bones pelted into his small body. He bit down on his lip, twisting his face downwards as tears threatened to slip through his eyelids. Sans winced.

"Ouch." He muttered, peering through one eye.

After that round ended, Jude managed to stumbled back to his feet. The fog, added to Papyrus's loud monologue, made it difficult for anyone to notice the pain the boy was in. Jude, swaying, was bruised and battered. His sweater once again torn, and…was that blood dripping from his nose? Understandably the boy sniffled.

"AND I WILL BE SUPER POPULAR-!" The sniffle cut Papyrus off. He stared "UH…HUMAN, JUDE, ARE YOU ALL RIGHT?"

"Oh…" Jude smiled "Y-yeah, I'm fine. Don't worry about it."

Sans snorted. The lights in his eye sockets flickered to his brother, watching him intently. Exasperated, Papyrus threw up his arms with a loud NYEH! With a few steps he was at the child, scooping him up quickly.

"YOU KNOW…" Papyrus started, strolling off back into the direction they came "FOR BARELY KNOWING SANS, YOU ACT A LOT LIKE HIM."

Sans trotted behind them, tilting his head at Papyrus's comment. Jude didn't seem to see him through the fog, and his attention was on the loud rambling skeleton anyway.

Papyrus dropped the pitch of his voice, mimicking Sans's " **No Pap, I'm fine, see?"** His eye sockets bulged out in the comic way his eyes do "THEN HE FALLS DOWN THE STAIRS BECAUSE HE'S MISSING A FOOT! AND THEN HE'S ALL-"

"Something strange is a-foot?" Jude interrupted with a bit of a giggle. Papyrus's eye sockets narrowed a moment, then he hollered out:

"YES! …HOW DID YOU KNOW THAT?"

Jude just shrugged. Papyrus took this as an answer and continued to carry the boy back to their house. Jude was even more of a mess than before. His sweater once again being taken to be mended. His arm was still bandaged up, the bruises on his face even more black and blue than before. And now, there were scraps and bumps adding to his accumulation of injuries. Jude hopped back onto the couch, pressing a tissue to his bleeding nose. Sans sat down next to him.

"Heya, kid." He greeted. Jude just smiled and waved. Sans gave him a skeptical look "Hey, why didn't you just say that Pap hurt you? He can't read minds, y'know."

Jude gave him a baffled look. "He was having fun."

Sans twitched, staring at the boy. After several moments of trying to find a response and failing, he gave up. Eventually, Papyrus brought back Jude's Sweater EX. He insisted it would never tear again. Jude just smiled (a tad awkwardly) and thanked him.

"NOW, JUDE…" Papyrus fidgeted "I…. I APOLOGIZE FOR HURTING YOU."

"It's okay." Jude smiled "You didn't mean to."

"YOU'RE RIGHT! FOR I AM FAR TOO AMAZING FOR THAT!" His grin dropped "BUT THE FACT IS I STILL HAVE. AND I'M SORRY."

"I….It's okay." Jude insisted, putting a small hand on his forearm "Here.. how about this? You be my friend, and we'll put all of that behind us."

"WOWIE, WHAT A DEAL!" Papyrus chirped, scooping Jude up in a hug "I ACCEPT!"

Jude laughed "Glad to hear it!"

Sans's grin hitched up a notch. He was still grinning as the boy strolled past his checkpoint. As always, he offered a meal to the kid. And not much changed except one thing. That being, when Sans handed Jude the ketchup, the boy's eyes narrowed at he went to tilt the bottle. Then, he set it back up straight and screwed the cap tight onto the bottle.

So Sans didn't have to give up his meal, which was good.

Afterwards, Jude went about his business in Waterfall. He followed the trends for a while. Befriend MK, had a run-in or two with Undyne. Eventually, Sans found himself waiting for the boy next to the telescope. And waited. And waited.

Sans yawned, drowsily looking down the damp path. With a bit of a sigh, he turned on heel and began a leisurely stroll. Sometimes a kid would get lost. It wasn't uncommon. Maybe a flower bridge puzzle held them up, or maybe they couldn't find the door in the wishing room. Kids taking this long wasn't unheard of. But as he strolled along, his non-existent ears caught on the sound of singing.

Blinking, Sans turned the corner to see Jude squatted next to a row of Echo Flowers, hands cupped around his mouth as he whispered to them. After finishing his sentence, he leaned back and tentavtively touch a blue petal.

" _La la la~!"_ called the echo flower. Jude jumped to his feet, sprinting along with the sounds, his fingers trailing along the edges of more petals. Each picked up the first one's song, passing it along as if it were playing hot potato. But as the song was passed, another layer of distortion was added, and the song became less and less gleeful until it was just a jumbled mess of white noise. This didn't seem to damper the boy's spirits, as he laughed softly when he was done panting. Then he ran up to the first flower again.

"Uh…heya, kid." Sans said, trotting up behind him. Jude jumped, almost toppling into the flower he was speaking to.

"H-hi, Mr. Sans." He greeted.

"'Mister'?" Sans repeated, raising a bone brow. "Er…a'right. What're you doing?"

"Oh…uh…" Jude fidgeted with the hem of his sweater, a light blush gracing his cheeks "I was just….uh….playing."

"Playing the Echo Flower?" Sans said "A fine choice of instrument."

"These flowers are instruments?" Jude exclaimed, eyes wide "Wow!"

Sans snickered, tugging at his sweater collar. "Er…yeah. Anyway…."

He hadn't really planned on what he was going to say next. Jude stared at him a moment, bronze eyes burrowing into the skeleton's SOUL. Then, suddenly, he gave a soft smile.

"Want to make the flowers sing again?" he offered.

Sans shrugged "Nah kid, seems like too much running." As the child's expression dropped, Sans piped back up "But hey, I'll stand here and listen to whatever you happen to compose, kay?"

"O-okay!" Jude sputtered, his smile growing wider. "I'll try to come up with something really nice for you!"

"Heheh." Sans chuckled, ruffling the boy's hair "Thanks." The child was staring up at him again, his eyes wide and glimmering. Sans blinked, startled "Uh…something up…?"

"You ruffled my hair." Jude observed. Sans tilted his skull.

"Sorry kid, not comfortable with that?"

"Oh- oh no! It's okay!" Jude said frantically, waving his hands in the air. His fingers ended up clasp about each other as he looked away bashfully "Just, no one's…."

Sans blinked. Jude shook his head, that soft smile back on his face "It's nothing." He turned and ran off to a flower, skidding to his knees in front of it to lean in, whispering. Sans watched him, head cocked, hands in pockets, thoughts a-racing.

Jude smiled at him, stumbled to his feet, and touched the Echo Flower's petal.

" _Laaa laaa laaaa laaaaaaaaa~!"_


End file.
